Outboard motors have a powerhead and a water propulsion device, such as a propeller. Typically, an internal combustion engine is positioned in a cowling defining the powerhead. The engine has an output shaft arranged to drive the water propulsion device of the motor.
The motor is movably mounted to the stern of a watercraft for propelling the craft in various directions. Generally, the motor is moveable about a vertical axis for use in steering the craft, and is tiltable about a horizontal axis for trimming the motor in an out of the body of water in which the craft is located.
If the size and weight of the outboard motor is excessive, it is difficult to turn and trim the motor, and the position of the watercraft in the water is detrimentally affected. In addition, the motor presents a surface which contributes to the aerodynamic drag of the watercraft. As such, the motor is generally made as small as possible, with the engine tightly positioned in as small of a cowling space as can be provided.
The positioning of the engine in the small space defined by the cowling is beneficial when considering the above-stated problems, but creates several other problems. A main problem is that the cowling traps the significant heat generated by the engine. This heat may damage components associated with the engine. For example, engine electrical features are often quite sensitive to high heat.
In some environments, complex liquid cooling systems are utilized to cool various engine features. In the outboard motor setting this solution is not available because this type of cooling system increases the weight and size of the engine.
It is an object of the present invention to provide an outboard motor arrangement which overcomes the above-stated problems.